I had a Carbon 97S. It functioned fine, but 5.56 can really kick hard in that lightweight body. The stock butt had no padding and a rough textured finish. Everytime I shot the gun, I had a bruise and sometimes a little bleeding on my shoulder. I debated getting an adjustable stock installed, but said the hell with it.
It was unpleasant to shoot, worse than any AK. I sold it after a few months.
Would I own another one? Maybe, if the price was right (meaning really low). But I'd definitely change the stock next time. There comes a point where an AR can be too light.